However, the acidity of phenol is more than that of ethanol. Reasons. In the gas phase, water is much less acidic than methanol, which is consistent with the difference in polarizibility between a proton and a methyl group. 11: Alcohols, Phenols and Ethers / Chemistry Examplar Problems Assertion : Ethanol is a weaker acid than phenol. 27 Votes) Phenol is more soluble in NaOH than in water is because phenol is slightly acidic. Hence, water is more acidic than ethanol. so they are the same and both dissolve in ethanol or acetic acid dissolves in ethanol because they are small molecules. (b) if both assertion and reason are true but reason is not the correct explanation of assertion. Regards Malik Xufyan (iii) Both o- and p-nitrophenols contain the NO 2 group which is an electron withdrawing group. The case of ethanol is rather simple to evaluate. Unlike water, alcohol does not conduct electricity due to a lack of free electrons. Reason : Lewis acid polarises the bromine molecule. True. Answer (1 of 10): Because of the electron donating nature of the alkyl group attached to the oxygen which destabilises the hydroxide ion and makes it tougher for the oxygen to donate the proton. Hence it is more a. Comparing methoxide and hydroxide ions, O is attached to a CH3 group in one and H in the other. Benzoic acid is less soluble in water than acetic acidbecause benzoic acid has a benzene moiety attached to it which is purely organic and non-polar in nature this decreases its solubility in water while ethanoic acid is more soluble because the organic part is smaller in size so it is can easily form Hydrogen bonds . phenol with sodium is a slower reaction because phenol is a weak acid. Besides, the volatility decreases when ethanol is mixed with water. Water on the other hand contain no such alkyl group so it can donate proton easily. The other alkyl groups have "electron-pushing" effects very similar to the methyl group, and so the strengths of propanoic acid and butanoic acid are very similar to ethanoic acid. An aqueous solution of phosphoric acid contains a greater concentration of dissolved ions than it does neutral phosphoric acid molecules. Miscible means that the material dissolves in water in all proportions so the question is moot. As we can see from the p K a data water is slightly more acidic than ethanol in water but in DMSO ethanol is notably more acidic. Copy. Its chemical formula is C 6 H 5 − O −. (b) Reaction with NaOH : Phenol dissolves in NaOH to form sodium phenoxide and water. Both acetic acid and phenol are ionized in aqueous solution and give acetate and phenoxide anion respectively.Now ,the strength of acid depends on relative stability of their concerned anion ( conjugate base ). Study now. While in case of alcohol no resonance stabilization takes place so no release of $\ce{H+}$ ion. Firstly, the hydroxyl proton could be donated to a strong base, although this only happens to a minimal degree in an aqueous solution as water is a much stronger acid than ethanol. Reason : Sodium ethoxide may be prepared by the reaction of ethanol with aqueous NaOH. Phenol. Water's higher polarity means that each water molecule "sticks" to other . The pKa. Wiki User. (A) Assertion: Inter-halogen compounds are better oxidising agents than halogens The last molecule, stearic acid, is a long long chain while both ethanol and CH3COOH are small molecules. Presence of electron withdrawing group increases the acidity of phenol by , stabilising phenoxide ion while presence of electron releasing group decreases the acidity of phenol by destabilising phenoxide ion. Phenols do not completely dissociate in water, but they are much stronger acids than aliphatic alcohols. The acidic substance has the tendency to produce H + ions when dissolved in water. 67. So ethanoate ion is more stable and therefore ethanoic acid is better acid. Best Answer. Also, keep in mind that carbolic acid is a liquid solution of phenol containing approximately \[5\% \]water. Of coarse H2O is neutral referred to water because it is the S A M E .Even water can be both acid A N D base at the same time, though a bit weaker acidic than H2S, but a bit more stronger base. 200+ 1.8k+ Explain the following observations: <br> Phenol is more acidic . Lower the pKa value, acidic strength increases. As the hydrocarbon part of an alcohol gets larger, the alcohol becomes less water soluble and more soluble in nonpolar solvents.Phenol is somewhat soluble in water.It acts as a weak acid in water, so a solution of phenol will be slightly acidic.. Thereof, why are alcohols and phenols soluble in water? (a) Alcohols and Phenols are soluble in water due to their ability to form oxygen bonds with . Acetylsalicylic acid is slightly soluble in water, with a limit of solubility reported as approximately 3 mg/ml at 25 Deg C. It is also soluble in ethanol at 50 mg/ml and will dissolve in solutions of alkali hydroxides and carbonates with decomposition. When exposed to air and light, phenol turns pink. Identify the correct reason for this characteristic of phenol. Reason : m- and p- Nitrophenols exist as associated molecules. Drinking alcohol (ethanol) and a lot of other simple alcohols are more volatile than water because they are less polar. Ethanoic acid is a weak acid, but it dissociates about 10^11 times more than ethanol. Reason : m- and p- Nitrophenols exist as associated molecules. Answer: Its all about the electronic effects. Also asked, is phenol more acidic than ethanol? IV.Matching Type 57. Ethanol is less acidic than water because of the electron donating nature of the alkyl group attached to the oxygen which destabilizes the hydroxide ion and make it tougher for the oxygen to donate the proton. Good acid : one which can easily loose H+ , but wont accept it back easily. (A) Assertion: Fluorine forms only one oxo acid HOF. Let us understand the reason why phenol is more acidic than ethanol. Therefore, phenol is a stronger acid than ethanol, On the other hand, ethanol is a weaker acid than water because electron releasing − C 2 H 5 . In DMSO hydrogen bonding is minimal so the acidity is primarily dependent on the acid and not the solvent it is in. I understand that the reason ethanol is less acidic than water is because the ethanol ion has an inductive effect where more electrons are donated to the oxygen, so it being more negative it is more likely to pick up a hydrogen again. Phenol undergoes Kolbe's reaction but ethanol does not. 449642794 . <br> Reason Phenol is more acidic than ethanol. Due to -R and -I effect of the -NO 2 group, electron density in the OH bond of substituted phenol decreases and hence the loss of proton becomes easy and therefore more acidic. Why is phenol acidic than ethanol? In phenol, pulling the pz electrons from the oxygen atom into the ring causes the hydrogen atom to be more partially positive than it is in aliphatic alcohols. Question 57. Why is HCl Ka so superior than water Kw? Therefore, the used solutions have high viscosity. Hence acetic acid is more acidic than phenol. Neither is more soluble than the other since both dissolve completely in all proportions. It's worth noting that phenol is more acidic than water, while alcohols are more acidic than water. Assertion: Chlorine water is a more permanent bleaching agent than sulphur dioxide. Assertion : Ethanol is a weaker acid than phenol. Carboxylic acids are more acidic than alcohols. A compound can be an acid or a base, but not both. Now, ethanol is a weaker acid than water because the electron releasing ethyl group increases the ethanol density on oxygen and consequently the proton will not be released easily. Click to see full answer. For example, trifluoro ethanol, CF 3 CH 2 -O-H is about ten thousand times more acidic than ethanol, CH 3 CH 2 -O-H. making the sodium phenoxide extra stable. making the sodium phenoxide extra stable. carbonic acid is a stronger acid than phenol. Both ethanol and propanol are alcoholic compounds that contain a hydroxyl group (-OH) as the functional group of the molecule. Phenol is more acidic than alcohols due to stabilisation of phenoxide ion through resonance. Thus phenol is a stronger acid than ethanol. revealed that suitable conditions, 0.5% sulfuric acid and 5-6% The high concentration (more than 2%) of sulfuric acid 9 w/v dry solid of CPW, temperature 116 ºC for 10-13 min, are can produce toxic compounds that can act as inhibitors for the given a higher yield of ethanol (5.8 g/L). •water having pH more than alcohol is more acidic than ethanol. Phenol is more acidic and ethanol is less acidic than water. When phenol loses an H + ion, the ion formed is known as phenoxide ion. Question 57. Regards Malik Xufyan The acetic acid is more acidic then the phenol because in resonating structure the acetic acid forms the equivalent structure. Hence acidic strength increases in the order given above. Reason: Fluorine does not have d-orbitals in its valence shell. Therefore, in the gas-phase, t-butanol is the most acidic alcohol, more acidic than isopropanol, followed by ethanol and methanol. For best chemistry videos for NEET/IIT / CBSE BOARDS on youtube please subscribe our youtube channel #Tomar chemistry tutorial indore # Best chemistry classe. ii. Aside from the qualitative comparison of the acid strength, we need a quantitative definition for the acid strength.This is where the pKa comes into play. Ethanol is miscible with water because it can form hydrogen bonds with water molecules (the -OH groups can form hydrogen bonds with H 2 O molecules). Can aspirin dissolve in ethanol? As before, the fact that water is less acidic than methanol . 642667198 . Matching Column Type Questions. Advertisement Remove all ads. But phenol does not react with aqueous Na 2 CO 3 or NaHCO 3. In the gas phase, water is much less acidic than methanol, which is consistent with the difference in polarizibility between a proton and a methyl group. This means it is much more easily lost from phenol than it is from aliphatic alcohols, so phenol has a stronger acidic property than ethanol. The alcohol has a lower boiling point than water, it evaporates at a faster rate as compared to . Carboxylic acids react with Na, NaOH, Na 2 CO 3 and NaHCO 3.But alcohols only reacts with Na. Answer (1 of 2): Methanol >Ethanol > Propanol The reason methanol is more acidic than ethanol is because the single bond from the second carbon is electron donating, which will not stabilize the negative charge of the deprotonated form of the alcohol. For best chemistry videos for NEET/IIT / CBSE BOARDS on youtube please subscribe our youtube channel #Tomar chemistry tutorial indore # Best chemistry classe. Phenol reacts with sodium and emit hydrogen gas. Download Solved Question Papers Free for Offline Practice and view Solutions Online. to form a Hydronium ion (H30). The solubility of salicylic acid decreases in the order of ethanol, ethyl acetate . 4.1/5 (2,775 Views . The negative charge formed as a result of losing an H + ion is not localised . Thus, aspirin is more soluble in ethanol than in water. Is water more acidic than alcohol? An acid as a proton (H^+) donor. Phenol>water>ethanol •phenol is more acidic than water because it has a tendency to lose H+ ion and form phenoxide ion and if water loses H+ ion it forms hydroxide which is not stabilized by resonance. I want to know why HCl is a much stronger acid than H2O.They have similar bond energies (H-Cl = 427 kJ/mol, O-H = 467 kJ/mol), so there should be easy to ionize both. A lot more acidic. B. carbonic acid is a stronger acid than phenol. Note: Ionization constant (Ka) of phenol is more than that of ethanol indicates phenol is more acidic than alcohol. When ethanoic acid dissolves in water, it donates H^+ to the water, hence it is said to be acidic whereas ethanol in water does not dissociate to any appreciable amount. Phenol is more acidic than ethanol because in phenol lone pair of electrons are utilized in resonance stabilization so bond length between O and H atom increases and $\ce{H+}$ ion is easily released. Assertion : o-Nitrophenol is less soluble in water than the m- and p-isomers. Check out the interesting article related to alcohol conduct electricity. This reaction involves adding an H 2 O molecule across a C=C double bond. water is a stronger acid than phenol. Thus ethanol is a weaker acid than water. Now we look stability of these carboxylate anion and alkoxide anion. When ethanoic acid dissolves in water, it donates H^+ to the water, hence it is said to be acidic whereas ethanol in water does not dissociate to any appreciable amount. Phenol is more soluble in NaOH than in water is because phenol is slightly acidic. why methanol more acidic than water but ethanol is not - Embibe. The chemical formula of phenol is C 6 H 5 − O H. An acid loses H + ions in water. ∙ 2011-01-04 23:42:25. Homework Statement Soooo.looking at Ka values, methanol is more acidic than water. From this reaction, we can say, phenol is more acidic than alcohol. It is shown that the mixing of water with the alcohols and acetone resulted in a positive deviation of viscosity, which reached the maximum value at the water mole fraction x 1 ∼ 0.7 for water-methanol, x 1 ∼ 0.72 for water-ethanol, x 1 ∼ 0.74 for water-propanol, and x 1 ∼ 0.83 for water-acetone binary mixture. Increasing order of acidity is ethanol water phenol.The phenoxide ion obtained after the removal of a proton is stabilized by resonance whereas the ethoxide loan obtained after the removal of a proton is destabilized by +I Effect of − C 2 H 5 group. This is due to the phenomenon is called resonation which stabilises the formation of phenoxide ions. The products are favored in the acid-base reaction: HI (aq) + NH3 (aq) NH4+ (aq) + I- (aq). The primary alcohol compound is more acidic as compared to secondary and tertiary alcohols. In fact, about ten orders of magnitude, eleven orders of magnitude more acidic than the alcohol. See Answer. Reason : Sodium ethoxide may be prepared by the reaction of ethanol with aqueous NaOH. Matching Column Type Questions. Option B is correct. Phenol is more acidic than alcohols. Reason: Chlorine water oxidises while sulphur dioxide reduces. Why is phenol more soluble in NaOH than water? 000+ 800+ 3:47 . phenol with sodium is a slower reaction because phenol is a weak acid. No, it is a compound with more than four carbons, so it is insoluble in water. . Also, both are the simplest among alcohols.Since ethanol has only two carbon atoms, there is only one . Why is ethanol pH 7? Due to this phenol is more acidic than ethanol. There is no such effect is water. As a result, alcohol does not ionize much in the water, and behaves like a neutral compound in an aqueous medium. Due to stabilised resonance of phenoxide ion, phenol is more acidic than ethanol. Ethanol's hydroxyl group causes the molecule to be slightly basic. Reson is, carboxylate anion is more stable than alkoxide anion. Therefore, we already know that the pKa for ethanol is 15.9 plus the pKa for the carboxylic acid, which is acidic as in this case is 4.8. . This inductive transfer of polarity tapers off as the number of transmitting bonds increases, and the presence of more than one highly electronegative atom has a cumulative effect. As before, the fact that water is less acidic than methanol . Dow's method is also used to produce phenol (from chlorobenzene by cumene process). It is true for all alcohols except methanol, which is slightly more acidic than water. True. The alcohol has a lower boiling point than water, it evaporates at a faster rate as compared to . Explain why phenol is more acidic than ethyl alcohol. Also asked, is phenol more acidic than ethanol? False. May be you should try starting over. 69. Besides, O is more electronegative than Cl, so it should "steal" the electron easier. Ethanol is less acidic than water because of the electron donating nature of the alkyl group attached to the oxygen which destabilizes the hydroxide ion and make it tougher for the oxygen to donate the proton. Ethanol is less acidic. 400+ . Previous Year Papers. Assertion: Phenol is more acidic than ethanol Reason: Phenoxide ion is resonance stabilized (a) if both assertion and reason are true and reason is the correct explanation of assertion. Unlike water, alcohol does not conduct electricity due to a lack of free electrons. Both phenol and ethanol are weak acids. Phenol is less acidic than o - nitrophenol as electron withdrawing (− N O 2 ) group increases the acidity of phenols while electron donating groups (− C H 3 , − O C H 3 ) decrease the acidity of phenols. This effect is missing in ethanol and therefore 2-chloroethanol is more acidic than ethanol due to -I effect of C l . However, in water the hydroxide ion is hugely stabilised by hydrogen bonding (the ethoxide is as . Hence, water is more acidic than ethanol. Ethanol is a polar compound since it has a terminal hydroxyl group. Why is salicylic acid soluble in ethanol? Because of the inductive effect of the chlorine atom, which stabilises the carboxylate anion, chloroacetic acid is more acidic than acetic acid. Because these reactions follow Markovnikov's rule , the product of the reaction is often a highly substituted 2 or 3 alcohol. Ethanoic acid is a weak acid, but it dissociates about 10^11 times more than ethanol. Thus phenol is a stronger acid than ethanol. Phenols are more acidic than alcohols. The reactions showing acidic nature of phenol are : (a) Reaction with sodium : Phenol reacts with active metals like sodium to liberate H, gas. Your reasoning is sound in that acetic acid is more polar than ethanol; however, both acetic acid and ethanol are miscible with water. The solubility data table shows that both benzoic acid and benzocaine are significantly more soluble in ethanol than they are in water. Thus will reduce the electron density on O of − O H group, resulting in weakening of O − H bond and thus makes the molecule acidic. Ethanoic acid is therefore weaker than methanoic acid, because it will re-form more easily from its ions. Phenol is more acidic than ethanol because phenoxide ion is more stable than ethoxide ion due to resonance. Ethanol is immiscible in water, so the benzoic acid cannot move from one layer to the other.